Born in Salford, Lancashire, and educated at a local university, Powell took up acting while an undergraduate, but had to wait a few years for his first major success, in the BBC's sci-fi series, Doomwatch in 1970. Having been unexpectedly killed off in the last episode of the original series, Powell became a pin-up and a household name, following up with starring roles in several BBC serials, including Sentimental Education and Jude the Obscure.
Then came another major break. Having been selected for the title role in the blockbusting mini-series, Jesus of Nazareth, in 1975, Powell overcame criticism of his lifestyle by marrying his long-standing girlfriend, the Pan's People dancer Babs Lord. Theirs is one of the most enduring showbusiness marriages in the UK.
In 1978, Powell struck out again in a new direction, taking the leading role of Richard Hannay in the third film version of The Thirty-Nine Steps. So convincing was he in the role of the Edwardian adventurer that two television series based on the short stories of John Buchan followed during the 1980s.
Having been criticised for not playing enough comedy roles (though in fact he had appeared in several Shaw adaptations, notably as Professor Higgins in Pygmalion, opposite Twiggy), Powell agreed to a request from his old friend and golf partner, comedian Jasper Carrott, taking the part of an incompetent detective in a succession of sketches that formed part of Carrott's television series. This was so popular with audiences that several full-length episodes of The Detectives followed, with Powell ably demonstrating his comedy potential.
Nowadays Powell appears in person less often, but his mellifluous voice is still much heard, on voice-overs, advertisements, and as a narrator of television programmes.